Rotary positioning fence

ABSTRACT

Embodiments provide systems, methods and apparatuses for positioning boards and other wood pieces in preparation for sawing/trimming. In embodiments, a continuous track loop conveys board stops slideably mounted to board stop guides positioned perpendicular to the direction of flow. A horizontal frame member provides a series of positioning guides through which a cam follower coupled to a board stop is diverted, thus adjusting the position of board stops in a direction perpendicular to the direction of flow without the use of braking devices or other added sources of mass, friction or vibration.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/228,580 filed Mar. 28, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/920,895 filed Jun. 18, 2013 and issued as U.S.Pat. No. 8,714,341, which is a continuation of U.S. patent applicationSer. No. 12/792,666, filed Jun. 2, 2010 and issued as U.S. Pat. No.8,490,777, which claims the benefit of U.S. Provisional Application No.61/183,880, filed Jun. 3, 2009, the entire disclosures of which areincorporated by reference herein.

TECHNICAL FIELD

Embodiments herein relate to the field of sawmill machinery, and, morespecifically, to systems, methods and apparatuses for positioning lumberfor presentation to a sawing station.

BACKGROUND

Sawmills and lumber mills typically route lumber through a series ofcutting and finishing stations. After exiting one station, the lumbermust be positioned for presentation to the next station. Thispositioning may take place during transportation of the lumber from onestation to the next. In certain stations, boards are trimmed at one orboth ends. Current systems often position boards lengthwise along aconveyor with evenly spaced lugs used to separate and convey the boardstowards the trimming station.

Conventional positioning systems often use conveyor chains to carryboards positioned lengthwise across the width of the conveyor, whilesimultaneously using pipe rolls or similar mechanisms to urge the boardstransverse to the direction of flow towards a fence that results in aworkpiece position where the defect line matches a downstream sawposition. Other workpiece positioning systems do not use the transverserolls, but rely instead on a positioning bumper to push wood intoposition (see for example U.S. Pat. No. 591,130).

In moving paddle fence systems, boards are pushed against positioningbumpers or “paddles” connected to chains that are configured in acontinuous moving loop. The paddles move in the direction of materialflow, parallel with the board conveyor chains and at the same velocity.The rotating chain and paddle concept allows more time for each board toreach its final destination than a traditional trailing fence design.

Speed and accuracy are critical in positioning lumber for presentationto sawing stations—inaccurate positioning leads to waste, while slowerspeeds limit output. However, in the current positioning systems,increasing the processing speed tends to cause a reduction in accuracy.Similarly, as the current systems are adapted to increase accuracy,speed is diminished. As planer optimization becomes more widelyaccepted, the need for positioning accuracy has increased. But lumbersystem speeds have increased to such an extent that the traditionaltrailing fences are not as effective as they once were, often resultingin the positioning systems causing a bottle neck in the processingsystem.

Existing paddle fence systems use mechanisms such as paddle brakes, airactuators, and/or hydraulic positioners to position paddles. Thesemechanisms increase the accuracy of positioning. However, they alsoincrease the complexity of the systems, add mass to the paddles, inducevibration and increase friction. Therefore, existing systems are limitedin their range of possible operation speeds relative to lug spacing andphysical size. To match the wider lug spacing configuration frequentlyused in sawmill board transfers while also matching the board transferspeeds, the currently available paddle fence systems must be physicallyextended to compensate for the vibration and other problems created bythe positioning mechanisms.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings. Embodimentsare illustrated by way of example and not by way of limitation in thefigures of the accompanying drawings.

FIG. 1 illustrates an isometric view of a moving fence apparatus inaccordance with various embodiments;

FIG. 2 illustrates a perspective view of a moving fence apparatus inaccordance with various embodiments;

FIGS. 3a-3e illustrate plan views of moving fence apparatuses inaccordance with various embodiments;

FIGS. 4a-4b illustrate side elevational views of moving fenceapparatuses in accordance with various embodiments;

FIGS. 5a-5b illustrate bottom views of moving fence apparatuses inaccordance with various embodiments;

FIGS. 6a-6b illustrate rear elevational views of moving fenceapparatuses in accordance with various embodiments; and

FIGS. 7a-7b illustrate an exploded view of components of a moving fenceapparatus in accordance with various embodiments.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which are shownby way of illustration embodiments that may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope. Therefore,the following detailed description is not to be taken in a limitingsense, and the scope of embodiments is defined by the appended claimsand their equivalents.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments;however, the order of description should not be construed to imply thatthese operations are order dependent.

The description may use perspective-based descriptions such as up/down,back/front, and top/bottom. Such descriptions are merely used tofacilitate the discussion and are not intended to restrict theapplication of disclosed embodiments.

The terms “coupled” and “connected,” along with their derivatives, maybe used. It should be understood that these terms are not intended assynonyms for each other. Rather, in particular embodiments, “connected”may be used to indicate that two or more elements are in direct physicalor electrical contact with each other. “Coupled” may mean that two ormore elements are in direct physical or electrical contact. However,“coupled” may also mean that two or more elements are not in directcontact with each other, but yet still cooperate or interact with eachother.

For the purposes of the description, a phrase in the form “A/B” or inthe form “A and/or B” means (A), (B), or (A and B). For the purposes ofthe description, a phrase in the form “at least one of A, B, and C”means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).For the purposes of the description, a phrase in the form “(A)B” means(B) or (AB) that is, A is an optional element.

The description may use the terms “embodiment” or “embodiments,” whichmay each refer to one or more of the same or different embodiments.Furthermore, the terms “comprising,” “including,” “having,” and thelike, as used with respect to embodiments, are synonymous.

The terms “lumber” and “boards” are used interchangeably herein to meanwork pieces laterally positioned on a transport/conveyor such that theirlengths are perpendicular to the direction of flow (i.e. extendingacross the width of the conveyor rather than along the length of theconveyor).

The terms “board stop” and “paddle” are used interchangeably and areherein defined as a moving fence component configured to be conveyedsynchronously with lumber in the direction of lumber flow for lateralpositioning of boards (i.e. positioning along an axis perpendicular todirection of lumber flow).

The term “cam follower” is herein defined as any component configured tobe translocated within a positioning guide. Cam followers in accordancewith various embodiments may include a pin, a ball bearing, or othercomponents and may be cylindrical, round, or of any other shape,solid/hollow, and/or made of any suitable material (e.g. a metal,polymer, or any resilient material known in the art). Cam followers maybe constructed as a single part/unit, or they may be constructedfrom/include two, three, four or more parts.

The term “continuous track loop” is herein defined to include, but isnot limited to, one, two, three or more continuous belts, chains, orother moving elements rotatable around rotating elements such assprockets, gears, wheels, rollers, etc. In some embodiments, acontinuous track loop includes a pair of chains/chain loops mounted onrollers/sprockets/wheels and driven simultaneously. In otherembodiments, belts or other similar components alone or in combinationmay be included. A continuous track loop may be configured to convey oneor more components, including board stops and board stop guides, and maybe adjustable to convey the components at a rate matching that of lumberflow.

The term “actuator” is herein defined as a device for converting asignal/energy into motion/force, and is intended to include any suchdevice powered for example, electrically, pneumatically, and/orhydraulically, in any combination. In embodiments, an actuator may beused to produce rotary or linear motion to position a guide selector,board, longitudinal/adjustable guide, or other component.

Embodiments may include applications in which a board is moved towardand/or held against a paddle or board stop. Other embodiments mayinclude applications in which a board is pushed laterally by a paddle orboard stop. Embodiments may include one or more rolls, skatewheelsand/or other similar mechanisms known in the art for pushing a boardlaterally toward a paddle or board stop.

Embodiments herein provide a moving fence for positioning of workpiecesprior to presentation to a processing station, such as an end sawstation. In various embodiments, boards conveyed along a conveyor in adirection of flow may be axially/laterally positioned on the conveyor bya moving fence apparatus positioned and with paddle stops movinggenerally parallel to the board conveyor. Embodiments of a moving fencemay convey paddles/board stops synchronously with lumber and may beadjustable to accommodate a range of lug spacing and/or lumber spacingconfigurations.

In addition, embodiments may provide components of a moving fence (suchas a board stop guide or positioning guide) that is configured to beintegrated with a pull back style moving fence (with or without aroller) and/or a push style moving fence. Positioning may includepulling/pushing the boards against the paddles or pushing/pullingpaddles against the boards. Some embodiments may include one or morerollers positioned in parallel with the direction of board flow, andsuch rollers may push/pull boards to paddles. Similarly, devices otherthan rollers may be utilized to move the boards towards the paddles. Inother embodiments, paddles/board stops may position boards by pushingthe boards, rather than by stopping the boards as they are pushed towardthe paddles/board stops.

Embodiments further provide a board positioning system configured forimproved accuracy and speed, using a series of positioning guides toposition boards. The use of such positioning guides reduces/eliminatesthe need for mechanisms such as brakes, air actuators, and hydraulicpositioners to position the board stops, thereby avoiding the increasein board stop mass, friction, resistance and vibration that are inducedby those mechanisms. As exemplified by the embodiments described,positioning guides may allow for a potentially unlimited range of lugspacing options and may consequently enable operation of such boardpositioning systems on shorter conveyances, which may be fitted toexisting processing operations. For example, common transfers may beused for both positioner and trimmer, avoiding inaccuracies and otherissues created through hand-offs between transfers. Thus, embodiments ofa moveable fence as described herein may be integrated by sawmilloperations to directly feed downstream processes and/or transferequipment already in place downstream.

In various embodiments, methods, apparatuses, and systems forpositioning workpieces are provided. In exemplary embodiments, acomputing device may be endowed with one or more components of thedisclosed apparatuses and/or systems and may be employed to perform oneor more methods as disclosed herein. In embodiments, a computing devicemay be coupled to an actuator, a track loop, and/or other components. Insome embodiments, a computing device may control positioning of acomponent, actuate an actuator to position a component, start/stopoperation of the track loop, etc.

FIGS. 1 and 2 show exemplary moving fence apparatuses in accordance withvarious embodiments. FIG. 1 illustrates an isometric view of a movingfence apparatus in accordance with embodiments. As illustrated, a roll99 may be rotatable around a roll shaft 98 in a direction generallyperpendicular to the flow of boards (arrow shows direction of flow),which is operable to move a board toward a paddle and/or to retain aboard against a paddle. FIG. 2 shows a perspective view of a movingfence apparatus in accordance with various embodiments.

As illustrated, an embodiment of a moving fence apparatus may include acontinuous track loop comprising two chains 86 mounted in parallel onrotatable members 82. Rotatable members 82 may be rotatable aroundshafts 84. Board stop guides 62 may be coupled to chains 86 by guidefasteners 68. A board stop 61 may be coupled to a board stop guide 62 bya slide mount 64. Board stop 61 may also include cam follower 66 coupledthereto that is adapted to engage one or more positioning guides andhelp facilitate desired lateral movement of the board stop 61 (see FIGS.4a and 4b ).

In various embodiments, a lead in support structure 10 may include aninitial positioning guide 25 (see FIGS. 5a, 5b ) that is generallydisposed parallel to the direction of flow and is adapted to initiallycontrol positioning of the board stops 61 prior to moving into a desiredposition to engage an end of a workpiece. In some embodiments verticalsupport member 10 lacks an initial positioning guide.

A horizontal or laterally displaced structure 20 may disposed relativeto the chains 86 (e.g. above or below), and adapted to help move boardstops 61 about board stop guides 62. A lateral positioning guide 26 (seeFIGS. 3a-3e, 5a, 5b, 7a, and 7b ) may be angularly disposed about thelateral structure 20 relative to the direction of flow, and be adaptedto cause lateral movement of the board stops transverse to the directionof flow. A plurality of fixed longitudinal guides 30 placed at intervalsalong lateral positioning guide 26 and which are generally parallel tothe direction of flow.

In various embodiments, a plurality of adjustable guides 50 may bemovably coupled to longitudinal guides 30, such that a continuouschannel may be defined from the lateral positioning guide 26 through thedistal end of an adjustable guide 50. In various embodiments, adjustableguide 50 may be pivotably coupled at their distal ends to one or moreshifting members 54.

In embodiments, the guides 25, 26, 30 and/or 50 may be sized toaccommodate a cam follower 66 that may be coupled to a board stop 61(see e.g. FIGS. 5a, 5b ). One or more guide selectors 46 may be disposedalong the horizontal positioning guide and adapted to direct the camfollower to transition from the lateral positioning guide to a selectedone of the longitudinal guides 30 and/or adjustable guides 50. A resetguide 70 may be disposed on a return side of the continuous track loopand configured to cause the board stops 61 to move laterally along theboard stop guides 62 to a desired position, such as a home position. Thehome position may be the same position as the position established inthe initial positioning guide 25.

In the operation of the illustrated embodiment, board stop guides aretranslocated along the length of the continuous track loop at the samerate as (and in parallel with) board conveyance along the boardconveyor. Board stops 61 are slideably mounted on board stop guides 62such that they are moveable along a plane perpendicular to the length ofthe continuous track loop. As board stop guides 62 are conveyed alongthe top and around the end to the underside of the apparatus, the resetguide 70 angles toward the vertical support 10, pushing/sliding theboard stops 61 along the board stop guides 62 toward a board stopstarting position, e.g. a home position.

As the board stop guides 62 are conveyed upward from the underside ofthe continuous track loop to the upper side of the continuous trackloop, cam followers 66 engage transition from engagement of the initialpositioning guide 25 to the lateral positioning guide 26 (see FIGS.3a-3e , top view, and FIGS. 5a, 5b , view from below). With the lateralpositioning guide 26 extending at an oblique angle within the horizontalplane, the translocation of a cam follower 66 along the lateralpositioning guide 26 repositions board stop 61 along board stop guide62, moving board stop 61 away from the starting position in a lateraldirection (i.e. across the width of the continuous track loop).

A guide selector 42 positioned near a longitudinal guide 30 (see FIGS.5a, 5b, and 7a, 7b ) is controlled by a guide selector actuator 46. In afirst position (FIGS. 6a, 6b ) guide selector 42 prevents entry of camfollower 66 into fixed longitudinal guide 30 as the cam follower 66 istranslocated along lateral positioning guide 26. In a second position,the guide selector 42 moves to block further translocation of camfollower 66 along the lateral positioning guide 26, thereby divertingthe cam follower 66 into the longitudinal guide 30. The diversion of thecam follower 66 to the selected longitudinal guide 30 may cause thecorresponding board stop 61 to generally stop translocation along boardstop guide 62. At this stage, board stop 61 has been roughly positionedand continues to be moved in a direction parallel to the directioncontinuous track loop.

In various embodiments, each longitudinal guide 30 may be pivotablycoupled to an adjustable guide 50. In the illustrated embodiments, eachadjustable guide 50 is pivotably coupled at its distal end, by a hingepivot 56, to a shifting member 54, which may shift laterally to move thedistal ends of the adjustable guides 50, thereby altering the angle ofadjustable guides 50, allowing for fine positioning of board stops 61.One or more actuators 97 may be coupled to the shifting member 54 tourge such lateral movement (i.e. perpendicularly to the direction oftrack loop operation). In various embodiments, the longitudinal guides50 can be adjusted by rotationally positioning the lateral structure 20to achieve the fine positioning.

In the embodiment illustrated, as cam follower 66 exits the distal endof adjustable guides 50, cam follower 66 and board stop 61 continue tomove along the continuous track loop toward the underside or return sideof the device, whereat cam followers 66 engage reset guide 70 to resetthe position of board stop 61 on board stop guide 62 to the startingposition. The translocation of board stops 61 on board stop guides 62along the continuous track loop is synchronized with the translocationof boards/lugs along a board conveyor, such that board stops 61 arebrought into contact with board ends. Thus, board stops 61 may be usedto adjust the lateral position of the boards as they approach asawing/trimming station or other processing station, first by grossposition adjustment (longitudinal guides) and then by fine positionadjustment (adjustable guide). The use of such guides allows forpositioning without the use of brakes, air actuators/hydraulic devicesand other mechanisms as part of the rotating elements, which increasemass, induce vibration and limit speed.

FIGS. 3a-3e show plan views of embodiments of a moving fence apparatus.As shown in FIG. 3a , each longitudinal guide 30 is associated with aguide selector 42 and actuator 46. Guide selector actuators 46 may be,for example, solenoids controlled by a computing environment (e.g. aprocessor, a scanner, etc.) to select the optimal fixed longitudinalguide to which each cam follower 66 should be diverted. Additionally,shifting member 54 and/or one or more actuators coupled to shiftingmember 54 may be controlled by the same computing environment or by adifferent computing environment to more finely adjust the position ofboard stops 61 as described above.

In FIG. 3a , a first cam follower 90 is shown in/near the initialpositioning guide 25 prior to repositioning of the board stop, with theboard stop in the starting position. A second cam follower 91 has beendiverted from the lateral positioning guide into a longitudinal guideand the coupled board stop has been correspondingly laterallyrepositioned along its board stop guide. A third cam follower 92 hasbeen diverted into another longitudinal guide at a greater distance fromthe starting position, the coupled board stop having beencorrespondingly repositioned further along the board stop guide.

FIGS. 3b, 3c and 3d show embodiments which include one or more rolls 99for moving boards laterally toward board stops. These embodiments areconfigured for pull applications, in which a board is driven against aboard stop by the one or more rolls.

FIG. 3e shows an embodiment in which a board stop pushes a boardlaterally into a new position, with the vertical arrow showing thedirection of the push. In this embodiment, the board stops are reversedin direction on their slide rails, allowing boards to be pushed to theirfinal positions. One or more rolls and/or skate wheels may be used toensure that the board remains against the paddle at the final position.

In various embodiments, the angle of the lateral positioning guide maybe adjustable in order to increase or decrease the rate of lateralmovement of the board stops about the board stop guides. In theillustrated embodiment, the angle of the lateral positioning guide withrespect to the direction of continuous track loop operation isapproximately 20°. However, the angle of the lateral positioning guidein various embodiments may be any angle within the range of 10°-80°. Insome embodiments, the angle of the lateral positioning guide may beadjusted manually, while in other embodiments, the angle of the lateralpositioning guide may be adjusted by an actuator. In an embodiment, someor all of the guides may be channels formed by removal of material froma solid structure, while in other embodiments some or all of thepositioning guides are formed by placing elements (e.g. rails, etc.) atthe desired intervals along a surface of the lateral structure.

Board stop guides 62 are shown in the figures as paired cylindricalelements, but the configuration of board stop guides 62 may vary widelyamong embodiments and may include one, two, three, four or morechannels, tracks, solid members, cylindrical/edged/grooved elements,etc. Similarly, board stops 61 are shown in the figures as beingslideably mounted to board stop guides 62 with a slide mount 64.However, guide mounts may vary widely among embodiments to includevarious elements (e.g. bearing based arrangements, or other slidemechanisms generally known in the art). A guide mount may be absent insome embodiments (e.g. board stops 61 may be slideably mounted directlyto board stop guides 62 without additional components).

FIGS. 4a and 4b illustrate side elevational views of a moving fenceapparatus in accordance with various embodiments. In the embodimentshown in FIG. 4a , the apparatus may be configured such that board stops61 are conveyed along a horizontal plane below the level of the guideselector actuators and guides. This configuration may help prevent dustand debris from boards from falling into the components, such as theguide selector actuators and guides, and interfering with properoperation. However, in other embodiments, lateral structure 20 may beoriented with guide selectors and and/or guides disposed below the levelof the board stops and/or the board stop guides. In various embodiments,the system may be configured to position the board stop along thedesired longitudinal guide, and then have a transverse roll, skatewheel, or other urging device push the board against the board stop(“pull” embodiments). In other embodiments, the system may be configuredsuch that the boards may be positioned by the board stops pushing themlaterally (“push” embodiments).

FIG. 4b shows an embodiment that additionally includes a roll 99rotatable around a roll shaft 98. The illustrated embodiment alsoincludes an actuator 97 for lateral positioning of the shiftingmember/adjustable guides, which provides fine positioning of board stops61.

FIGS. 5a and 5b illustrate sectional views of a moving fence apparatusin accordance with various embodiments. The view illustrated in FIG. 4ais a sectional view from below the section marked in FIG. 3a , showingthe underside of the lateral structure 20 from the vantage of ahorizontal plane between the lateral structure 20 and the chains 86.Likewise, FIG. 4b is a sectional view from below the section marked inFIG. 4b . Guide selector stops 49 are shown in proximity to guideselectors 42 (see also FIGS. 7a and 7b ). Guide selector actuator 46 maybe coupled to guide selector 42 by a guide selector pivot 44, and isrotatable in opposite directions about guide selector pivot 44, suchthat guide selector actuator 46 can move the corresponding guideselector 42. When a guide selector 42 is positioned to block lateralpositioning guide 26 and to divert a cam follower into the correspondinglongitudinal guide, the guide selector 42 may be prevented fromover-rotating (unblocking the lateral positioning guide) by a guideselector stop 49, which stops the guide selector 42 in a position fordiverting the cam follower into the longitudinal guide. FIG. 5b alsoshows an embodiment that includes an actuator 97 coupled to shiftingmember 54 and operable to shift the adjustable guides 50. In thisillustration, the adjustable guides 50 have been slightly shifted forfine adjustment of board stop position, as described above.

In various embodiments, e.g. those with solenoid actuators, selection ofa longitudinal guide for diversion of a cam follower may be accomplishedby sending a signal from a computing environment to the actuatorcorresponding to the selected longitudinal guide. Some or all of theguide selectors may be positioned to block a longitudinal guide at restand to block the lateral positioning guide upon activation of theactuator, while in other embodiments, some or all of the guide selectorsmay be positioned to block the lateral positioning guide unless/untilthe corresponding actuator is activated.

While the illustrated embodiments include both longitudinal guides andadjustable guides, in various embodiments, longitudinal guides may bethemselves adjustable. In such embodiments, the longitudinal guidesbecome adjustable guides that are pivotally coupled to a longitudinalpositioning guide at intervals along the lateral positioning guide. Insome embodiments, series of adjustable guides may be pivotably coupledconsecutively, end-to-end, and each series of adjustable guide may bepivotally coupled to a lateral positioning guide. In an embodiment ofthis type, each adjustable guide section may be limited to amaximum/minimum range within which the guides may be adjusted, providingfor varying degrees of adjustment along the length of the lateralstructure 20. Additionally, embodiments comprising adjustable guideswithout longitudinal guides may include any/all of the means of guideselection described above.

FIGS. 6a and 6b illustrate rear elevational views of a moving fenceapparatus in accordance with various embodiments. FIG. 6a illustrates arear elevational view of a moving fence apparatus that may be adaptedfor push and/or pull applications. FIG. 6b illustrates an embodimentthat includes a roll 99 rotatable around a roll shaft 98, and anactuator 97. In this figure, a board is shown being pushed against aboard stop 61 by the roll 99. As shown in the figures, each board stop61 may be separately positioned across the width of the continuous trackloop. While the illustrated embodiments use the continuous track loopconfiguration shown, continuous track loop mechanisms are well known inthe art. Embodiments vary as to the continuous track loop mechanismemployed, including any/all such mechanisms known in the art. Forexample, a continuous track loop may be powered or non-powered, may be aroller/belt/chain conveyor, and may include a chain drive for powertransmission. In some embodiments, a continuous track loop may bepowered by another conveyor and/or the drive used to power anotherconveyor. The embodiments described herein are exemplary and are notintended to be limiting as to the continuous track loop mechanisms orother mechanisms known in the art and included within the variousembodiments.

FIGS. 7a and 7b illustrate magnified views of components of a movingfence apparatus in accordance with various embodiments. Guide selector42 is shown coupled to a guide selector pivot 44 generally at or nearthe interface of lateral positioning guide 26 and a longitudinal guide30. Guide selector pivot 44 is coupled to guide selector actuator 46,which may be coupled to the lateral structure 20. In FIG. 7a , a guideselector 42 is shown blocking longitudinal guide 30. In FIG. 7b , aguide selector 42 has been pivoted into position to divert the camfollower 66 from the positioning guide 26 into longitudinal guide 30.

Although certain embodiments have been illustrated and described herein,it will be appreciated by those of ordinary skill in the art that a widevariety of alternate and/or equivalent embodiments or implementationscalculated to achieve the same purposes may be substituted for theembodiments shown and described without departing from the scope. Thosewith skill in the art will readily appreciate that embodiments may beimplemented in a very wide variety of ways. This application is intendedto cover any adaptations or variations of the embodiments discussedherein. Therefore, it is manifestly intended that embodiments be limitedonly by the claims and the equivalents thereof.

What is claimed is:
 1. A rotary positioning system for repositioningboards as the boards are conveyed along a path of board flow,comprising: a board stop assembly including a continuous track loopoperable in a first direction of flow, a board stop guide coupled to thecontinuous track loop in an orientation generally perpendicular to thefirst direction of flow, and a board stop slideably mounted to the boardstop guide; a guide assembly including a lateral positioning guideextending transverse to the first direction, and a plurality of secondguides coupled with the lateral positioning guide and extendinggenerally in the first direction, the second guides being spaced apartat intervals across the first direction, wherein the lateral positioningguide and the second guides are configured to engage the board stop; andan actuator coupled with the guide assembly, wherein the actuator isselectively actuable to move a downstream end of the second guidestoward and away from the path of board flow.
 2. The rotary positioningsystem of claim 1, further comprising a plurality of third guidesconnected to the lateral positioning guide, wherein each of the secondguides is pivotally coupled at a first end to a respective one of thethird guides and pivotably coupled at a second end to a shifting member,and wherein the actuator is operatively coupled to the shifting member.3. The rotary positioning system of claim 2, wherein the actuator isselectively operable to translocate said shifting member laterally tothereby move the downstream end of said second guides toward and awayfrom the path of board flow.
 4. The rotary positioning system of claim1, wherein the second guides are adjustable about an upstream end of thesecond guides.
 5. The rotary positioning system of claim 1, furthercomprising a guide selector disposed along the lateral positioning guideand a second actuator coupled to said guide selector, wherein the secondactuator is selectively operable to move the guide selector between afirst position, in which a corresponding portion of the lateralpositioning guide is blocked by the guide selector, and a secondposition, in which a corresponding one of the second guides is blockedby the guide selector.
 6. The rotary positioning system of claim 5,wherein said second actuator is a solenoid.
 7. The rotary positioningsystem of claim 1, wherein the lateral positioning guide is disposed atan angle of between 10 and 80 degrees relative to the first direction offlow.
 8. The rotary positioning system of claim 1, wherein said lateralpositioning guide is positioned generally above said board stop.
 9. Therotary positioning system of claim 8, wherein the board stop includes acam follower, and the guides are configured to engage the cam follower.10. The rotary positioning system of claim 1, wherein said lateralpositioning guide is positioned below said board stop.
 11. The rotarypositioning system of claim 1, wherein the guides are coupled to alateral structure, and the lateral structure is rotationallypositionable to thereby adjust an angle of the second guides relative tothe first direction.
 12. The rotary positioning system of claim 1,further comprising a support member configured to support the guides ina generally horizontal plane.
 13. The rotary positioning system of claim12, wherein the support member includes an initial positioning guidedisposed upstream of the lateral positioning guide and orientedgenerally parallel to the first direction of flow, and wherein theinitial positioning guide is configured to engage the board stop. 14.The rotary positioning system of claim 13, further including a returnguide coupled with the support member and extending transverse to thefirst direction of flow, wherein the return guide is configured toengage the board stop to thereby return the board stop to a desiredstarting position upstream of the initial positioning guide.
 15. Therotary positioning system of claim 14, wherein the guides are disposedabove the continuous track loop and the return guide is disposed belowthe continuous track loop.